Dissemination of evidence-based practices remains a high priority at NIDA. A number of barriers limit accessibility to these effective practices in routine community-based treatment settings. Persons with severe and persistent mental illness (SPMI) commonly experience both substance use disorders (SUD) and borderline personality disorder (BPD), resulting in serious and complex personal costs and public nealth problems. Although Assertive Community Treatment (ACT) is efficacious for persons with SPMI, it is less clear the extent to which this approach adequately meets the needs of substance dependent BPD clients. Dialectical Behavior Therapy for Substance Use Disorders (DBT-SUD) is an efficacious psychosocial treatment for individuals with BPD and co-occurring SUD. Over the past decade, this combined approach of DBT-SUD within ACT has been identified as a promising direction for clinical practice and more ACT teams are using DBT to work with their most difficult-to-treat SPMI clients. [unreadable] [unreadable] We propose to develop and pilot-test an innovative computer-based training aimed at training ACT providers in effective strategies to reduce in-session dysfunctional behaviors. Specifically, the CBT will focus on the following objectives: 1) understanding the rationale for applying the DBT-SUD In-Session Response to Dysfunctional Behaviors protocol, 2) learning the protocol s seven steps, and 3) identifying and applying the necessary components of each step in the protocol. The Phase I prototype will include one case-based scenario to facilitate learning. An iterative process of prototype development will be used where end-user feedback will drive prototype modifications to ensure its usability and acceptability. An advisory board of DBT experts, ACT experts, and ACT providers will also be used to ensure that the prototype is scientifically sound, and that it fits with the ACT philosophy and approaches, while maintaining fidelity to the DBT-SUD model. Feedback will be obtained using individual interviews, online reviews, and live-user testing. Once the initial goals of usability and acceptability are achieved, we will conduct a randomized controlled pilot test (n=30) to evaluate gains in content knowledge, recall, and self-efficacy in applying the DBT-SUD In-Session Response to Dysfunctional Behavior within ACT Teams. [unreadable] [unreadable]